Apparatus for grinding lenses.



-J. BROCKBANK.

APPARATUS FOR GRINDING LENSES.

APPLICATION FILED NOV. I6. I915.

LQQLQSU Patented Apr. 3, 1917- 10 SHEETS-SHEET l.

J. BROCKBANK. APPARATUS FOR GRINDING LENSES. APPLICATION FILED NOV. 16,I915- 1,21 2%, Patented Apr. 3, 1917.

I0 SHEETS-SHEET 2.

J. BHOCKBANK.

APPARATUS FOR GRINDING LENSES. APPLICATION FILED NOW-16.1915. v

1 ,QQl ,Qfifl I I Patented Apr. 3, 1917.

I0 SHEETS-SHEET 3- 1 36 Aim I 1. BROCKBANK APPARATUS FOR GRINDINGLENSES. APPLICATION FILED NOV. 16, I915.

LQQLQEOI Patented Apr. 3,1917.

I0 SHEETS-SHEET I II 1. BROCKBANK.

APPARATUS FOR GRINDING LENSES,

APPLICATION HLED NOV. 16, 1915.

mamww PatentedApr. 3, 1917.

I0 SHEETS-SHEET 5- J. BROCKBANK.

APPARATUS FOR GRINDING LENSES.

APPLICAT'ON mm NOV.16. 191s.

Patented Apr. 3, 1917.

10 SHEETS-SHEET 6.

1. BROCKBANK. APPARATUS FOR GRINDING LENSES.

APPLICATION FILED NOV. 16. I915.

LQQLWQ, Patented Apr, 3,1917.

v SHEET 1.

$0 SHEETS- i. BROCKBANK. APPARATUS FOR GRINDING LENSES.

APPLICATION FILED NOVKIS; I915- Patented Apr. 3,1917.

l0 SHEETS-SHEET 8.

m fia/l J. BHOCKBANK.

APPARATUS FOR GRINDING LENSES. APPLICATION FILED NOV. yfi. 1915.

Patented Apr. 3, 1917.

10 $HEETS- SHEET 9.

Hall

Y J. BROCKBANK. APPARATUS FOR GRINDING LENSES. APPLICATION HLED NOV. 16.1915.

m mm Patented Apr. 3,1917. 10 SHEETS-SHEET l0.

JOHN BROCKJBANK, OF SYDNEY, NEW SOUTH WALES, AUSTRALIA.

APPARATUS FOR 7 GRIN DIN G LENSES.

Specification of Letters Patent.

ti Patented Ap 3, 4L

Application filed November 16, 1915. Serial N 0. 61,782.

To all whom it may concern:

Be it known that I, JOHN BRooKBANK, a subject of the King of GreatBritain and Ireland, residing at Lombard Chambers, Pitt street, Sydney,in the State of New South lVales, Commonwealth of Australia, haveinvented certain new and useful Improvements in Lenses, of which thefollowing is a specification.

This invention relates to improvements in apparatus for grinding lensesand has for its object to carry out the process as described in theapplication for improvements in the process of grinding lenses.

The apparatus has been constructed as to enable various forms and shapesand powers of lenses desired to be carried out.

The apparatus consists essentially of a framing having bearings for apair of spindles mounted upon a common'axial line and carrying on theiropposing ends blanks, which blanks are held in contact with one anotherduring the grinding action. One of the spindles is also'adapted to movethrough an arc and the other spindle to move axially and when thedesired shape of lens or lenses has been achieved the grinding actionceases automatically.

In order to produce lenses of any power required the spindle that movesin an arc is adapted to be adjusted to alter the length of the radius ofthe arc throu h which the blank is adapted to move an scale beinattached for the purpose, also aflixed to the apparatus is another scaleand indicator to obtain the length of the cord of they are required.This spindle is also adapted to be locked so as not to rotatewhen movingin an are when other shaped lenses are required.

The other spindle besides movingaxially can also move laterally and beprevented from rotating for further differently shaped lenses.

But in order that. the invention and the method of carrying it out maybe clearly understood reference will now be made to the drawings whichaccompany this complete specification and in which Figure 1 is aperspective view of the apparatus complete.

Fig. 2 is a front elevation thereof.

Apparatus for Grinding Figs. 3 and 4 are sectional elevations onlines.33 and 4-4 respectively in Fig. 2. B Fig. 5 is a sectional plan'online 55 in Fig. 6 is a sectional elevation on line 6-6 in Fig. 3.

Fig. 7 a front elevation of a modified form of construction of theapparatus.

Fig. Sis a sectional elevation on line 8-8 in Fig. 7

Figs. 9 to 30 are diagrammatic views illustrating the process ofgrinding.

Referring to Figs. 1 to 6 which illustrate a machine by means of whichlenses can be ground by in process. The framing 31 has bearings 32 or;the main driven spindle 33 which is provided with a pulley 34. On thespindle 33 is a miter wheel 35 gearing with a miter wheel 36 on avertical spindle 37 in bearings 38 alsocontained in the framing 31. Onthe top end of the vertical spindle 37 is a miter wheel 39 gearing witha miter wheel 40 that is on one end of the horizontal spindle 41 thathas bearings 42 in a sleeve 43. The sleeve 43 has also a bearing 44 inthe main frame 31 and has two projecting members 45 which form'bearings46 for the vertical spindle 47 that has a miter wheel 48 gearing withthe miter wheel 49 on the horizontal spindle 41. The spindle 47 has athird bearing 50 in the extension bracket 51 which bracket has avertical slot 52 and clamping screws 53 which take into the twoprojecting members 45. The miter wheel 48 is slidably aiiixed to thevertical spindle 47 which is vertically adjustable by means of thebracket 51 and collar 54. The spindle 47 has at its lower end a chuck orface plate 55 to which is attached a blank of glass or the like 56constituting one of the opposing surfaces to be ground as hereinbeforemenwhich is connected with the crank disk 61 by rod 58 which isadjustable by means of the crank pin 59 which takes in slot 60. Thecrank disk 61 is mounted upon a horizontal spindle 62 supported inbearings 63 in bracket 64 that is secured to the main framing 31; Thedisk 61 also forms a miter Wheel which gears with the miter wheel 65upon the vertical spindle-66 that has bearings 67 in the main frame 31.At the lower The" second opposing surface 70 which n'gv either be ablank of glass or hard a radingmaterial is oppositely disposed and heldby a chuck or mounted upon' a face plate 71 on the end of the verticalspindle 72 which is in the same straight line-as spindle 47. The spindle72 has bearings 73 in block 74 which is adapted to move laterally on'theblock 75 which in turn is vertically slidable in the bed 76.. Thespindle 72 is slidably adjustable and has a coil spring 77 and anadjustable collar 78 and is rotated by the universal joint 121 and cable122. The vertical slide block 75 is secured 2 in desired position by aclamp nut 79 on the lug 80 whlch takes in the vertical'slot 81 inframing 31. The lateral slide block 74 which has a clamping screw" 82 isadjusta- 'bly connected to the crank disk 86 by connecting rod 83 andcrank pin 84 which is movable in slot 85. v.The crank disk 86 is mountedon spindle 87 which has bearing in block 88 that is slidable in thevertical slot 89 in framing 31 and is provided with a f 0 clamping nut90. On the opposite end of the spindle 87 is a miter wheel 91 whichgearswith a miter wheel 92 that is adjustably afiixed on the verticalspindle 93 that has bearings 94. This spindle 93 has also 7 anothermiter wheel 95 gearing with a miter wheel 96 upon a counter-shaft orspindle 97 in bearings 98 and which has also a toothed wheel 99 gearingwith a toothed wheel 100 l .7 upon the driven spindle 33 hereinbeforementioned.

5 In the vertical slot 81 in the framing 31 'is a sliding block 101 witha clamping bolt 102. This block has an index finger 103 which is adaptedto register with the marked scale 104 and is-provided for the purpose ofascertaining the length of radius from the axial line of spindle 41necessary for producing the required curved surface. Aflixed to thebearing 44 is a sector plate 105 having marked thereon a scale 106preferably of degrees. Adapted to register with this scale 106 is afinger 107 afiixed to the radial arm 57 on sleeve 43 for the purpose ofdetermining the curvature of the face and has an indicating finger 107adapted to regs the diameter of lens that is to beproduced.

ister with the scale 106 marked on the front 'face of' the framing. Theradial arm 109 has bearings 46 for the vertical spindle 47 which has aslidably aflixed miter wheel 48 andan adjustable collar 54.

The spindle 47 has a chuck or face plate 5.5 to which the blank 56 ofglass or other material constituting one of the opposing surfaces issecured. The spindle 47 has also a miter wheel 48 gearing with a miterwheel 49 on a spindle 41 in'a bearing 110 which forms part of the radialarm 109. The spindle 41 is driven by auniversal joint 111 and cable 112.The radial arm 109 has a pair of lugs or pins 113 and 114, and a similarpair of In s or pins 115 and 116 are provided on the ront face of theframing 31. A coil s ring 117 is adapted to be connected to eit er ofthe pins or lugs 113 and 114 on the radial arm 109 and to the lugs 115and 116 upon the framing according to requirements. The radial arm 109is adapted t'o'ktake against an adjustable stop 118 in the' quadrantgroove 119 in the framing 31. The spindle 72 with the face plate 71 9and blank 70 are mounted and o erated in a manner similar to that hereinefore described.

Again referring to Figs. 1 to 6 the operatlon of the' machine is asfollows The shaft or spindle 33 isdriven by the pulley 34 and conveysits motion to the vertical shaft 37 through the miter wheels 35 and 36thence to the horizontal spindle or shaft 41 by the miter wheels 39 and40. The horizontal spindle or shaft 41 trans; mits its motion to thevertical spindle 47 which carries the blank or opposing surface 56. Thespindle 47 has a pendulum motion imparted to it by the crank disk 61 andconnecting rod 58 which enga es the radial arm 57 onsleeve 43, thuscausmg the blank to move through an arc, whose center is theintersection of' the axial line of horizontal spindle-41 with the axialline of vertical spindle 47. The len th of this radius of swing may be.varied raising or lowering the vertical spindle 4'; in its bearings 46.The crank disk 61 is set in motion by the miter wheel 65 upon thevertical spindle 66 115 which spindle receives its motion from the adriven shaft or spindle 33 by the miter wheels 68 and 69.

The are of movement to be given to the spindle 47 which determines thecurvature of the face of the lens is ascertained b the movement of thefinger 107 which reglsters with the indicator plate 105 and the desiredmovement is obtained by adjusting thethrow of the crank in 59 in slot 60of crank disk 61. The mac ine is adjusted to obtain the correct radiusof swing of the s indle 47 in the followingmanner. The pomter 103 onsliding block 101 is set to register the desired radius on the scale'l04thevspindle 47 1 0 together with the bearing bracket 51 is then raisedor lowered until the axial center point on' the opposing surface 56 isin alinement with the pointer 108. The opposing blanks 56 and 7 O areaffixed to the face plates 55 and 71 in any suitable manner such as bypitch or the like. The lower opposing blank 70 after being aflixed toits face plate 71 on the spindle 72 has its axial center brought intoalinement with the axial center ofthe blank 56, so that the axes of thetwo spindles 47 and 72 are in the same straight line. This adjustment ofthe spindle 72 is accomplished by the slide block 74 and clamping screw82. The surface of the blanks are then brought into contact with. oneanother by the slide I block 75 and clamp screw 79. Between the faceplate 71 and the bearing 73 is a clearance space. for the purpose ofallowing the lower opposing member 70 to be depressed bythe upper member56 during theprocess as hereinafter referred to. This" movementiscontrolled and adjusted by the setting of the collar 78 upon thespindle 72. The

coil spring v77 is provided for the purpose of keeping the opposingsurfaces 56 and in contact under pressure during operation. The spindle72 receives its rotary motion through the universal joint 121 and cable122 and both opposing members 56 and 70 are adapted to rotate in thesame or in opposite directions as required.

When 16:15 desired that the slide block 74 should be .rec'iprocated toperform another function, the clamp screw 82 is released'and the crankpin 84 adjusted to the throw required and the disk 86 is then set. inmotion by its spindle 87 being driven by the miter wheel 91 gearing withthe miper wheel 92 upon the spindle 93 which has atmiter wheel 95gearing with a miter wheel 96 upon the counter shaft 97, the countershaft 97 being driven by the gear wheel 99 gearing with the gearwhe-el'100 upon the driven shaft 33. The disk 86 is thrown out of actionby disconnecting gears 91 and 92.

Referring to Figs. 7 and 8 the operation of the machine is as follows Inthis case the radius of swing is measured from the axis of the fixed pin108 to the axial center on the lower surface of the blank 56 and iscorrectly fixed as before explained with the aid of the index finger onindicator plate 120.

The spindle 47 is rotated by the miter wheels 48 and 49, universal joint111 and cable 112.- The coil spring 117 is provided to exert a pull uponthe radial arm 109 during the rotation of spindle 47 and cause theopposing surface 56 to move through an arc of predetermined radius, thecenter of whiph is in the common axial line of the spindles and measuredfrom the axial line of the fixed pin 108. The position of the'block 118del termines that are of movement.

In order to fully describe the process of grinding lenses as carried outby the machine herein described, reference will now be made to Figs. 9to 30 which are diagrammatic views illustrating the process for theproduction of ordinary lenses. Referrmg first to Figs. 9 to 13 the twoopposing blanks 56 and 70 are of glass and the apparatus as describedwith referenceto Figs. 1 to 6 s used. The gear wheel 100 is unmeshedfrom the gear wheel 99 by any well known means thus throwing the crankdisk 86 out of gear.

Both blanks 56 and 70 are then brought into contact with each other andadjusted so that their axial centers correspond with the axes of thespindles 47 and 72 which axesf I are in one and the same straight line.

The spindles 47 and 72 are then caused to rotate in the same directionand simulta- *neously the spindle 4.7 is given a pendulum action whichcauses the contactingsurface of the blank 56 to grind .away in themanner shown in Fig. 10 While the rotating blank 70 has its surfacehollowed out (see Fig. 10). The coil spring 77 maintains the surfaces inconstant contact under pressure until finally the surfaces of bothblanks 56 and 70 have acquired the curves of predetermined radius seeFig. 11 which illustrates the lenses produced viz. a plano conyex and apiano-con: cave. lens. If it is required to produce a double convex anda double concave lens the blanks 56 and'70 have their curved surfaces Iaffixed to their respective face plates 55 and 71 see Fig. 12 and theprocess being repeated complete lenses are produced as-shown in Fig. 13.The ordinary powdered grinding medium of various grades is introducedbetween the opposing surfaces during the process.

Referring to Fig. 14. When it is desired to produce a lens without theuse of grinding power, one of the surfaces 56 is com-' posed ofhardabrading material such as carborundum or the like while the other blank70 is of glass. A repetition of the process hereinbefore describedwillpro'duce a plano-concaveor a double concave lens.

Referring to Fig. 15. If the positions of the blanks are reversed thatis to say the blank 56 is of glass and the blank 70 is carborundum aplane-convex or double convex lens-is produced.

Referring to Figs. 16 to 22 which illustrate the process for theproduction of what are termed cylinders, and using as before the machineillustrated in Figs. 1 to 6.

To produce simultaneously a plus and minus cylinder as illustrated inFig. 18; the opposing blanks 56 and 70 are of glass. In this caseneither of the blanks rotates but turning ofi the power andlocking it byscrew 128 which takes into groove 124 pI'eVQnt1I1g l@ blanks arereversed that is to say 56 is of carborundum and 7 0 is of glass and aminus cylinder is produced. (Fig. 22.)

As hereinbefore mentioned 7 the machine described and illustrated inFigs. 7 and 8 is particularly suitable for carrying out the process forthe production of lenses of high ower that is to sa lenses havin a curve7 3 of small radius. The process as carried out by this machine isillustrated in Figs. 23

' ferring to Figs. 23 and 24 the blank 56 ji'ofr glass and the'blank 70ofcarborundum 2E .or the-like. The blanks are first centered in 1 themanner hereinbefore described (see Fig.

Both blanks are caused to rotate, but instead of oscillating the spindle4:7 as before, a pull is exerted on it from a point above the center ofswing in order to cause the surface-56 to move through an arc duringtheprocess of grinding. The pull is exerted by the coil 's ing 117 which isattached to the spindle fiat 114 and to the'framin'g at 116. Theadjustable stop 118 determines the arc of movement. The' lenses may becompleted with two curved surfaces if required.

In Figs. 25 and-26 both blanks 56' and 70 are of glass and plano-convexand planoconcave or double convex and double concave lenses areproduced. p

In Figs. 27 and 28 the blank 56 is of carborundumand the blank 70 is ofglass. In this case the coil spring 117 is positioned on the other sideof the spindle 47 being attached to lug 113 on radial arm and lug 115 onframing. This arrangement produces a piano-concave or double concavelens.

copies of this patent mey be obtained for Referring to 29 and 30, andusing the machine illustrated in Figs. 1 to 6.

If the blank 7 0 does not rotate but is re-,

polishing device.

What I claim as my invention is 1. An apparatus for grinding lensescomprising a pair of spindles mounted upon a common axial line andadapted to carry on their opposing ends blanks, both spindles rotatableand one spindle adapted to move through an arc and the other to moveaxially and laterally all for the purpose as herein ascertained.

2. An apparatus for grinding lenses comprising upper and lower spindlesmounted upon a common axial line and adapted to carry on their opposingends blanks, a resilient spring for maintaining the contact of theblanks, means for inclining the upper spindle, means for imparting tosaid lower spindle a reciprocatory movement and means for pressing thelower blank against the upper one.

3. An apparatus for grindin lenses comprising upper and lower spin lesmounted upon a common axial line and adapted to.

carry on their opposing ends blanks, a resilient spring for maintainingthe contact of the blanks, means for inclining the, upper spindle, acrank disk and connecting rod for reciprocating the lower spindle, and aresilient bufier against which one of said blanks is axially movablewith its spindle under pressure of the other blank.

Signed at Sydney, New South Wales,Au'stralia, this 30th day of Au st, A.D. 1915.

' J OHN B OCKBANK. Witnesses:

A'. COPLAND ROBERTSON JOHN Eves.

five cents each, by addressing the commissioner of Patents, Washington,D. II."

